Process for the production of artificial stone, stoveware, and the like from boiler slag, dust slag, or ashes



Patented Apr. 13, 1926.

UNITED STATES PATENT OFFICE.

FRIEDRICH KORBER, OE DUSSELDOBF, AND WILHELH HESSEL, OF ESSEN-RUHB,

. GERMANY.

PROCESS FOR THE PRODUCTION OF ARTIFICIAL STONE, STONEWA RE, AND THE LIKE FROM BOILER BLAG, DUST BLAG, OR ASHES.

No Drawing. Application filed June 7,

To all 'whom it may concern:

Be it known that we, FRIEDRICH Korean and WILHELM HESSEL, citizens of the German State, residing, res ectively, at 14 Men- 6 delsohnstrasse, Dussel orf, Germany, and

10 boiler slag, dust slag, or ashes, of which the following is a specification.

It is known to produce stone ware of every description, such as building stone and other massive and hollow blocks for constructional purposes, also platform and pavement flags, pantiles, tubes, chimney stones, kneading troughs, insulators and the like from coal clinker (boiler slag, dust slag or ashes). Hitherto it has been customary to add to the clinker or slag a binder, such as lime, cement, clay or silicates in a finely divided form. The stone ware thus produced is of a colour that is little suited for outdoor building purposes and its degree of hardness is comparatively low.

Furthermore, stone ware produced by the known method often contains injurious constitutents which affect its quality very appreciably.

According to theinvention the coal clinker after being reduced or ground is first moulded and then subjected to sintering. Thus the binder hitherto usually employed is entirely dispensed with. By-regulating the degree of fineness to which the clinker or slag is ground and also the temperature of combustion, the sintering of the moulded body proceeds inwards uniforml and by reason of the particles being pointed and having constituents which. scorify upon reaching the sintering temperature, a material of great strength and hardness is produced. In the case of fairly large pieces the operation of sintering can be assisted by providing recesses and grooves therein. Byintermittently or otherwise increasing or reducing the thermal action the stone wane is given the desired qualities-glassy or rough surface, compactness, permeability, etc.

The sintering process can be influenced 1924. Serial No. 718,872.

ducing the stone article desired, and pressure then applied. The bodies formed are then subjected to the sintering process in a furnace, for example, a tunnel furnace, under the conditions of temperature above referred to, that is with intermittent increase, reduction or interruption of the thermal action. After cooling, the stone ware thus produced is at once ready for use.

According to the invention light porous stone ware, similar to pumice-stone, can be produced in known manner by the addition of combustible substances, such as sawdust, cork-waste, short-straw, peat, and the like.

Moreover the stone ware may be provided with a coating by means of a spraying device, such coating adhering firmly to the surface.

The stone ware produced by this new process is distinguished by great strength and hardness, sharp edges, insensibility to weather conditions, most exact retention of v the original size and shape, and also by uniformity of colour.

The technical and industrial progress involved in this invention is clear from the foregoing. The utility of the process is enhanced by the fact that the fuel residues previousl separated out from the clinker or slag can e directly used for supplying the necessary heat for sintering, for example, by firing with powdered coal. The waste heat of the sintered products and of the waste products carried away to be cooled may be used for generating power. In this way the present invention effects a saving in fuel, which in the known processes is required for the production of the cement, lime, or other binder hereinbefore referred to, and it also substances of the character of coal clinker 10 meet-S the demand for the complete utilizasuch as slags comprising the reduction of the tion of the waste products which have hereclinker or slag to a finel divided condition, tofore been looked upon as valueless or of moulding the finely divided clinker or sla 5 little value. The great quantities of clinker into the form of the object to be produced or slag, available in various industries can and then sintering the moulded body, sub- 15 thus be economically utilized. stantially as described.

We claim: FRIEDRICH KORBER.

A process for producing stoneware from WILHELM HESSEL. 

